Communication devices may transmit and receive communication data through a communication medium. In one example, the communication medium may be a wireless communication medium where the communication data (e.g., radio frequency signal) is transmitted and received by communication devices according to a wireless communication protocol. Example wireless communication protocols may include IEEE 802.11 protocols and Bluetooth protocols according to the Bluetooth Special Interest Group. In another example, the communication medium may be a wired communication medium where the communication data is transmitted and received according to a wire-based communication protocol. Some example wire-based protocols may include an Ethernet® protocol and/or a Powerline Communications protocol described by the HomePlug 2.0 specification. In yet another example, the communication medium may be a hybrid combination of both wired and wireless communication mediums.
Some communication protocols may use quadrature signals to transmit and/or receive the communication data through the communication medium. For example, a communication protocol may use an in-phase (I) clock signal and a quadrature (Q) clock signal (sometimes referred to as a local oscillator signal) to encode and/or decode the communication data. In some communication devices, the generated I and Q clock signals may include one or more unwanted signals that may interfere with the performance of the communication device. For example, unwanted harmonics of the I and Q clock signals may undesirably couple into a sensitive receive and/or transmit circuit and interfere with the transmission and/or reception of the communication data.
Thus, there is a need to improve the generation of signals (such as I and Q clock signals) and suppress and/or reduce unwanted signals associated therewith to improve the performance of the communication device.